Apparatus for controlling watercraft and similar transport vehicles are known in the art. Known watercraft control apparatus, however, suffer from certain drawbacks.
In particular, watercraft control apparatus of the prior art include a first transmission line for mechanical control signals that receives mechanical control signals from a mechanical control signal input unit, such as a rudder wheel, a steering wheel, a control lever or the like. For example, a first mechanical control signal transmission circuit or line may mechanically connect a rudder wheel, a steering wheel, a control lever or a similar device to a power-consuming unit, such as a rudder, a motor or a similar device.
A second transmission line for electric or electronic control signals may also be included in watercraft control apparatus of the prior art to provide a power-assisted mechanical control. Such second line acquires a control signal corresponding to a mechanical signal inputted by a user, for example, to a force, a displacement or another type of mechanical input, and converts that mechanical signal into a corresponding electric/electronic or hydraulic control signal.
When this second electric or electronic transmission line or control circuit is provided, the mechanical signal is transduced into a corresponding electric/electronic control signal through a transducer system of the optical or electric type, typically a potentiometer. Consequently, the signal provided by the force and/or the displacement of the rudder, of the control lever or, more generally, of the control member is converted into a corresponding control signal for an actuator actuating the power-consuming unit.
Therefore, this electric/electronic circuit turns the control signal generated by the user on the control member into a corresponding electric/electronic signal actuating a load operating system, or directly controls the load or power-consuming unit, alternately or in combination.
In one example of the prior art, the system transducing mechanical control signals into a corresponding electric/electronic control is optical. An optical system acquires the displacement, that is, a mechanical signal, and turns it into a corresponding electric/electronic signal. With an optical sensor, proper detection of the control signal closely depends on the cleanliness of the sensor, because an improper cleaning may cause incorrect or wrong detection of the control signal, which is thus transmitted incorrectly or is not transmitted at all.
Marine environments are highly aggressive and might greatly affect cleanliness and proper operation of an optical device. Particularly, if the control apparatus is located on the watercraft deck or in an area of the watercraft that is particularly exposed to weather and environmental agents, oxidation and salt are likely to cause an early fouling of the optical control signal detection system.
In another example of the prior art, an electric system may be employed, in which the control member is operably connected to a potentiometer detecting the mechanical control and turning it into a corresponding electric control signal, which is transmitted to an actuator, to the power-consuming unit, or to a controller.
Potentiometers are particularly sensitive to oxidation in marine environments and prone to deterioration, which causes a malfunctioning of the potentiometer and hence a malfunctioning of the electric/electronic control circuit.
More particularly, the electric contacts of potentiometers are sensitive to oxidation and do not operate properly when oxidized. Furthermore, the conformation of potentiometers makes them not easily serviceable, causing a replacement of the potentiometer in the event of failure.
In addition, transducers have a physical configuration that makes access difficult, regardless of being of the optical, electrical or potentiometric type. The extensive maintenance required by prior art transducers, to maintain them in a clean and non oxidized state, is particularly cumbersome, time-consuming and costly.